Synchronization of a stereoscopic camera

ABSTRACT

A method for synchronizing the recordings of two video cameras which are operated in parallel for the three-dimensional representation of an image sequence, in particular, of two digitally recording video recorders, a light signal being faded into the image area of the two cameras and simultaneously recorded by both cameras; and the playback of the recordings being synchronized using the recorded signals.

[0001] The present invention relates to a method for synchronizing the recordings of two video cameras which are operated in parallel for the three-dimensional representation of an image sequence, in particular, of two digitally recording video recorders. The present invention likewise relates to a system for implementing this method.

[0002] In the domain of professional film and video recordings, cameras are known which permit parallel recording of image sequences via two equally oriented lenses. The synchronization of the cameras and of the projectors is carried out electronically, requiring a corresponding outlay. Due to the high financial outlay, these systems are not suitable for the private user, especially because the handling of the complex systems requires appropriate training.

[0003] It is an object of the present invention is to provide a method which permits high-precision synchronization of the recordings of two commercial video cameras using simple and inexpensive means. It is also an object of the present invention to devise a system for implementing the method.

[0004] It is an essential aspect of the present invention to bring a light signal into the field of view of the two cameras running in parallel and, optionally, to record an acoustic signal which is simultaneously recorded by the cameras and which can be used during playback for synchronizing the recordings. Via the light signal, sort of a “movie clapperboard” is implemented for the two cameras. In this context, it is unimportant whether one and the same light signal is recorded with both cameras or whether each camera records a separate light signal. However, it is required that two light signals occur at the same time, which is advantageously accomplished in the case of two light-emitting diodes via a common voltage supply. When the recordings are later mixed together, the light signals are used as marks for synchronizing the two films.

[0005] The advantages of the present invention lie in the possibility of simple and inexpensive implementation. Using the present invention, it is possible to use commercial video recorders to record three-dimensional films. In this connection, the synchronization is so precise that a high-quality 3-D representation results therefrom. By the present invention, 3-D recording becomes interesting to the mass market. When using digital cameras, playback is possible on conventional PC's and television sets. The present invention offers the user the experience of plastic vision. Thus, the 3-D effect is made possible without PC animation.

[0006] It is advantageous for the two cameras to be combined on a common mounting to form one system. The system according to the present invention is then provided with means which make it possible for at least one light source to be positioned at least temporarily in the field of view of both cameras. Then, both cameras can be operated like a single one. It is inexpensive and therefore particularly advantageous to implement the means by way of a hinged holding device with which a light source is swung in front of both lenses or in each case one light source is swung in front of each of the two lenses simultaneously.

[0007] To simplify operation, it is also advantageous to couple the releases of both cameras mechanically or electronically. In a particularly advantageous embodiment, the light sources are switched on upon actuation of the common release. In this manner, it is guaranteed that when the two recordings are later cut together, they can be synchronized at the beginning of each film sequence. To be able to check the synchronization quality also within the running film sequence, it is advantageous that the light source be positioned in front of the lens or lenses and switched on in a cyclically repeated manner. In addition, it is advantageous to provide control electronics which allow the two light sources to be switched on simultaneously.

[0008] The light sources can be implemented particularly easily using light-emitting diodes. These are available in any desired size, luminosity, or color and, due to the low afterglow, are especially suitable for generating short-time light signals.

[0009] In the following, the present invention will be explained in greater detail with reference to the FIGURE.

[0010] The FIGURE is a schematic view of two camcorders 1 of the classic type with their lenses 2 and their electronics 3.

[0011] Both are mounted on a common mounting which is not shown. The image sequences picked up by the camcorders can be tapped via signal lines 4. According to the present invention, both camcorders 1 are coupled via common control electronics 5 to which is connected a common release 6.

[0012] According to the present invention, provision is made for means (not shown) which make it possible to temporarily swing in each case one light-emitting diode 7 in front of each of lenses 2. Light-emitting diodes 7 are synchronously excited also by control electronics 5 to which they are connected via lines 8. 

What is claimed is:
 1. A method for synchronizing the recordings of two video cameras which are operated in parallel for the three-dimensional representation of an image sequence, in particular, of two digitally recording video recorders, wherein in both cameras (1), a light and/or acoustic signal is/are faded in which is/are simultaneously recorded by both cameras (1); and the playback of the recordings is synchronized using the recorded signals.
 2. The method as recited in claim 1, wherein one light source (7) is positioned in front of each of the two lenses (2), respectively, the two light sources (7) being switched on simultaneously via one voltage supply.
 3. The method as recited in claim 1 or 2, wherein the releases of both cameras (1) are coupled mechanically or electronically.
 4. The method as recited in one of the preceding claims, wherein the light sources (7) are switched on for a short time upon actuation of the common release (6).
 5. The method as recited in one of the preceding claims, wherein the light sources (7) are switched on in a cyclically repeated manner.
 6. A system comprising two video cameras which are mounted on a common mounting for parallel recording of the same image sequence, characterized by means which make it possible for at least one light source (7) to be positioned at least temporarily in the field of view of both cameras (1).
 7. The system as recited in claim 6, wherein the means feature a hinged holding device with which in each case one light source (1) is simultaneously swung in front of each of the two lenses (2).
 8. The system as recited in claim 6 or 7, characterized by control electronics which allow the two light sources (7) to be switched on simultaneously.
 9. The system as recited in one of the claims 6 through 8, wherein a light source (7) is a light-emitting diode. 